We have a unique problem with our 2004 Hyundai Sonata. When it's hot weather and the car is parked on concrete or asphalt, the car sputters upon takeoff. It also sputters and doesn't seem to want to go in the 40 to 50 mph range. If the car has not been parked on concrete or asphalt it doesn't do this. Has anyone else had this issue? Any suggestions as to the cause of this problem would be greatly appreciated.